Wire pulling head apparatus with crimp zone indicators and method of using same

ABSTRACT

An enhanced apparatus and method for securing a wire to a pulling cable for pulling wire. Specifically, the pulling cable and wire are attached via a pulling head body. The wire is inserted into an end of the pulling head body and secured by crimping the pulling head body against the wire. Further, crimp zone indicators positioned on the outer surface of the pulling head body indicate the optimal zone of crimping to achieve substantial contact between the pulling head body and the wire. A pulling cable is secured to the pulling head body via a ball swage that comprises a tapped surface.

CROSS-REFERENCE TO RELATED APPLICATIONS

Not applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

REFERENCE TO A COMPACT DISK APPENDIX

Not applicable.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to pulling head bodies for pulling wires, andmore particularly, to wire pulling head bodies having crimp zoneindicators for facilitating proper crimping of the pulling head bodyonto the wire.

2. Description of Related Art

To distribute electricity throughout a building, insulated electricalwires are installed between the power source and power distribution boxand routed to electrical boxes to supply electricity to a device. Often,these electrical wires are routed through multiple conduits throughoutthe building, and these conduits can span great distances and caninclude numerous twists and turns. As such, installing electrical wiresthroughout a building has presented both logistical and mechanicalchallenges.

The wire and cable industry have used many means for pulling wirethrough the building's infrastructure. For example, electric-poweredmachines have been used to pull the wires through the various conduitsof the building's infrastructure. These wire pulling machines pulledwire through the building by applying a pulling tension to a pullingcable that was linked to the electrical wire. The pulling cable and wirewere linked via a pulling head body. The pulling cable was attached toone end of the pulling head body, and the wire was secured to theopposite end of the pulling head body. To secure the wire to the pullinghead body, an operator would insert the wire into the pulling head bodyand would use a crimping device to crimp the pulling head body againstthe wire.

During the crimping process, the position of the crimp on the pullinghead body was estimated by the operator. For example, in some instancesthe operator would use a measuring device to determine where to crimpthe pulling head onto the wire. In other instances, the operator wouldvisually estimate the correct crimping position. Because of these crudetechniques, often times an operator would place the crimp too close tothe pulling cable side of the pulling head body. Sometimes, the resultwas that the crimp did not make enough contact between the pulling headbody and the wire, and the wire would become detached from the cableduring pulling. Alternatively, in some cases, the operator placed thecrimp too close to the wire side of the pulling head body. The resultwas a weak crimp due to its close proximity to the end of the pullinghead body. Again, the effect was the detachment of the wire from thepulling cable during a wire pull.

Inconsistent crimping resulted in pulling failures during a costly wirepull, loss of time, costs involved reattaching the wire to the pullinghead, and the repeat of the process often many times before completesuccess. Although the crimps were occasionally properly positioned, thecrimping procedure and sufficiency of engagement was at bestinconsistent, time intensive, and required actual measuring of distancesfor crimp position by use of a separate device.

In addition, another potential point of failure occurred at theattachment between the pulling cable and the pulling head body. Thepulling cable was attached to the pulling head body by some form ofattachment means. During some wire pulls, the attachment means wouldfail, and the pulling cable would become detached from the wire.

Thus, there is need in the art for a more precise method of crimping apulling head body to a wire to ensure that the wire remains secured tothe pulling cable during a wire pull. What is needed is a pulling headbody that enables a user to quickly and easily identify consistent andproper crimp zones, by way of a surface marking system, for providingproper attachment of a pulling head to a wire, all without the use ofadditional measuring devices or the need to reaccomplish the crimpingprocedure with additional devices and equipment. Furthermore, there isneed for a more secure connection between the pulling cable and thepulling head body to prevent the pulling cable from detaching from thewire. What is needed is an attachment means designed with an improvedgrip to prevent the pulling cable from detaching from the pulling headbody.

SUMMARY OF THE INVENTION

The present disclosure is directed to apparatuses and methods forpulling wire. In one preferred embodiment, a wire is linked to a pullingcable via a pulling head body. The pulling head body comprises one ormore crimp zone indicators on the outer surface of the pulling headbody. The crimp zone indicators indicate the approximately optimalposition for crimping the pulling head body against a wire.

In another embodiment of the invention, a pulling cable is secured tothe pulling head body via a ball swage that engages with the innersurface of the pulling head body. The ball swage is crimped to the endof the pulling cable, and the inner surface of the ball swage is tappedto increase friction between the ball swage and the pulling cable.

A further embodiment of the invention comprises a method for linking apulling cable to a pulling wire. A pulling cable is inserted into afirst end of a pulling head body. A ball swage is crimped to the end ofthe pulling cable such that when tension is applied to the pulling cablethe ball swage engages with an inner surface of the pulling head body. Awire is inserted into a second end of the pulling head body. Using acrimping device, an operator secures the wire to the pulling head bodyby crimping the pulling head body against the wire such that theposition of the crimp dimples are substantially centered with respect toone or more crimp zone indicators positioned on the outer surface of thepulling head body.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The foregoing summary, as well as the following detailed description,will be better understood when read in conjunction with the appendeddrawings. For the purpose of illustration, there is shown in thedrawings certain embodiments of the present disclosure. It should beunderstood, however, that the invention is not limited to the precisearrangements and instrumentalities shown.

In the drawings:

FIG. 1 illustrates a side view of a pulling head body according to anembodiment of the invention;

FIG. 2 illustrates a first end of a pulling head body according to anembodiment of the invention;

FIG. 3 illustrates a second end of the pulling head body according to anembodiment of the invention;

FIG. 4 illustrates a side sectional view of the pulling head bodyaccording to an embodiment of the invention;

FIG. 5 illustrates a ball swage attached to an end of a pulling cableaccording to an embodiment of the invention;

FIG. 6 illustrates a side sectional view of the pulling head body withball swage attachment end of pulling cable operationally engagedaccording to an embodiment of the invention;

FIG. 7 illustrates a close-up side sectional view of the pulling headbody with ball swage attachment end of pulling cable operationallyengaged according to an embodiment of the invention;

FIG. 8 illustrates two pulling head bodies attached to a split pullingcable according to an embodiment of the invention;

FIG. 9 illustrates a side view of the pulling head body with crimpdimples substantially centered with respect to crimp zone indicators onthe outer surface of the pulling head body according to an embodiment ofthe invention; and

FIG. 10 is a graphical depiction of the wire pulling process utilizingthe pulling head body with crimp zone indicators according to anembodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Before explaining at least one embodiment of the invention in detail, itis to be understood that the invention is not limited in its applicationto the details of construction and to the arrangements of the componentsset forth in the following description or illustrated in the drawings.The invention is capable of other embodiments and of being practiced andcarried out in various ways. Also, it is to be understood that thephraseology and terminology employed herein are for the purpose ofdescription and should not be regarded as limiting. It should beunderstood that any one of the features of the invention may be usedseparately or in combination with other features. Other systems,methods, features, and advantages of the invention will be or becomeapparent to one with skill in the art upon examination of the drawingsand the detailed description. It is intended that all such additionalsystems, methods, features, and advantages be included within thisdescription, be within the scope of the present invention, and beprotected by the accompanying claims.

The present disclosure is described below with reference to the Figuresin which various embodiments of the present invention are shown. For thepurpose of clarification, embodiments described herein reference theterm “cable,” which refers to a pulling cable protruding from a “firstend” of a pulling head body. Also, references are made to the term“wire,” which refers to a wire product that is inserted into a “secondend” of the pulling head body. In other words, the wire is the objectwhich is pulled by the pulling cable via the pulling head body.

Referring to FIGS. 1, 2, and 3 by way of non-limiting example, andconsistent with embodiments of the invention, a pulling head body 5 isshown. The pulling head body 5 is manufactured such that it has alongitudinal, tubular shape, and has a substantially hollow two-partinternal bore structure. As depicted in the drawings, the longitudinalaxis of the pulling head body 5 runs between a first end 15 of thepulling head body 5 and a second end 20 of the pulling head body 5. Thepulling head body 5 further comprises a tapered end 25 that begins onthe outer surface 10 of the pulling head body 5 and tapers at an angletoward the first end 15. The pulling head body 5 further comprises aprimary internal bore extending longitudinally between the first end 15and second end 20 of the pulling head body 5. In a preferred embodiment,the primary internal bore is comprised of at least two different sizeinner diameter bores—a first end bore 17 and a second end bore 23. Thefirst end bore 17 extends longitudinally from the first end 15 to thesecond end bore 23. The second end bore 23 is continuous with the firstend bore 17, and terminates at the second end 20 of the pulling headbody 5. The first end bore 17 is designed to easily receive common typesand sizes of pulling cables 40 (Shown in FIG. 5). The second end bore 23is designed to easily receive common types and sizes of wire 65 (Shownin FIG. 9).

In a preferred embodiment, the first end bore 17 is continuous with thesecond end bore 23 via a second tapered surface 18, which tapersoutwardly from an end of the first end bore 17 into an end of the secondend bore 23. In this way, the first end bore 17 and second end bore 23are continuous, and the diameter of the first end bore 17 is smallerthan the diameter of the second end bore 23. Furthermore, the secondtapered surface 18 is tapered at an angle that can vary with the gaugeof the wire 65. By way of a non-limiting example, for a 1000 kcmil gaugewire, the second tapered surface 18 can be designed to taper outwardlyat an angle of approximately 120 degrees from the first end bore 17. Thesecond tapered surface 18 operates to minimize movement of a ball swage45 during wire pulling, which is discussed in more detail below.

The pulling head body 5 can be manufactured from aluminum, steel, or anyother sufficiently strong and rigid material as one of skill in the artwould contemplate for wire pulling uses. It is also understood that thelength, first end bore 17 diameter, second end bore 23 diameter, andouter surface 10 diameter of the pulling head body 5 can vary, and canbe manufactured to accommodate any size of pulling cable 40 or wire 65,depending on the size of wire to be pulled and needs of the operator.

Referring to FIG. 1, the outer surface 10 of the pulling head body 5 isfurther designed to include one or more crimp zone indicators 30. Thecrimp zone indicators 30 are disposed at predetermined strategic zoneson the pulling head surface 10 of the pulling head body 5. In this way,the crimp zone indicators 30 indicate the approximate optimal positionfor crimping, such that when wire 65 is properly inserted into thepulling head body 5, a crimp substantially centered with respect to thecrimp zone indicators 30 will achieve substantial contact between thepulling head body 5 and the wire 65.

The crimp zone indicators 30 can be flush with outer surface 10, etchedinto the exterior of the outer surface 10, or raised from the outersurface 10. For example, an etched or raised crimp zone indicator 30could include, but is not limited to, notches, grooves, depressions,striations or ridges. Furthermore, the crimp zone indicators 30 cancomprise various shapes and sizes. The crimp zone indicators 30 can alsospan the entire diameter of the pulling head body 5, or alternatively,can be positioned on one or more sides of the pulling head body 5. It isunderstood that the appearance, design or size of the crimp zoneindicators 30 is not limited, so long as it is visible to the naked eyeduring operation, and so long as it identifies an approximate optimalcrimping zone. In this way, the crimp zone indicators 30 provide for aconsistent and accurate indicator for the area for which a crimpachieves substantial contact between the pulling head body 5 and thewire 65.

The position of the crimp zone indicators 30 is directly related to thegauge of the wire 65. As discussed above, the pulling head body 5 can bemanufactured to a plurality of lengths, first end bore 17 diameters,second end bore 23 diameters, and other internal bore measurements andangles. The placement of the crimp zone indicators 30 are predeterminedand disposed on the pulling head body 5 during its manufacturing processbased upon the size of the end product pulling head body 5. Table 1illustrates some examples of positions of crimp zone indicators 30. Forexample, for gauges of wire 65 less than or equal to 4/0 AWG, the firstcrimp zone indicator is placed approximately ¾″ from the second end 20of the pulling head body 5, and the second crimp zone indicator isplaced approximately 1¾″ from the second end 20 of the pulling head body5. For wire 65 gauges between 250 kcmil and 400 kcmil, the first crimpzone indicator is placed approximately 1¼″ from the second end 20 of thepulling head body 5, and the second crimp zone indicator is placedapproximately 2½″ from the second end 20 of the pulling head body 5.Finally, for wire 65 gauges between 500 kcmil and 1000 kcmil, the firstcrimp zone indicator is placed approximately 1¼″ from the second end 20of the pulling head body 5, and the second crimp zone indicator isplaced approximately 2¾″ from the second end 20 of the pulling head body5.

TABLE 1 Illustrative Predetermined Positions of Crimp Zone IndicatorsApproximate Approximate Location of Location of # of # of Wire CrimpZone Crimp Zone Crimps at Crimps at Gauge Indicator 1 Indicator 2Location 1 Location 2   6 AWG ¾″ 1¾″ 1 crimp 1 crimp   4 AWG ¾″ 1¾″ 1crimp 1 crimp   3 AWG ¾″ 1¾″ 1 crimp 1 crimp   2 AWG ¾″ 1¾″ 1 crimp 1crimp   1 AWG ¾″ 1¾″ 1 crimp 1 crimp  1/0 AWG ¾″ 1¾″ 1 crimp 1 crimp 2/0 AWG ¾″ 1¾″ 1 crimp 1 crimp  3/0 AWG ¾″ 1¾″ 1 crimp 1 crimp  4/0 AWG¾″ 1¾″ 1 crimp 1 crimp 250 kcmil 1¼″ 2½″ 1 crimp 1 crimp 300 kcmil 1¼″2½″ 1 crimp 1 crimp 350 kcmil 1¼″ 2½″ 1 crimp 1 crimp 400 kcmil 1¼″ 2½″1 crimp 1 crimp 500 kcmil 1¼″ 2¾″  2 crimps  2 crimps 600 kcmil 1¼″ 2¾″ 2 crimps  2 crimps 750 kcmil 1¼″ 2¾″  2 crimps  2 crimps 1000 kcmil 1¼″ 2¾″  2 crimps  2 crimps

It is understood that the positions of the crimp zone indicators 30indicated in Table 1 are merely illustrative, and do not limit the scopeof the invention. A person of ordinary skill in the art would alsounderstand that the positioning of the crimp zone indicators 30 has anacceptable degree of error. For example, for wire 65 gauges between 6AWG and 4/0 AWG, the crimp zone indicators 30 can be positioned withinan error of approximately ⅛″. For wire 65 gauges between 250 kcmil and1000 kcmil, the crimp zone indicators 30 can be positioned within anerror of approximately ¼″.

In an alternative embodiment, the crimp zone indicators 30 also indicatethe location of a tapped surface within the exposed surface of thesecond end bore 23. After crimping, this tapped surface can provide forgreater friction between the pulling head body 5 and the wire 65. Thetapped surface can be textured, striated, ridged, furrowed or any othersurface that would increase friction between the pulling head body 5 andthe wire 65.

Referring now to FIGS. 5, 6 and 7 by way of non-limiting example, andconsistent with embodiments of the invention, a pulling cable 40attached to a pulling head body 5 is shown. The pulling cable 40 issecured to the pulling head body 5 by engagement of a ball swage 45 withthe pulling head body 5. Engagement of the ball swage 45 with thepulling head body 5 is more clearly depicted with reference to FIG. 7.The ball swage 45 is fixed to the pulling cable 40 via a neck 50, whichis crimped against an attachment end of the pulling cable 40. The ballswage head 55 is engaged with the second tapered surface 18 within thesecond end bore 23. Due to its tapered angle, the design of the secondtapered surface 18 functions to minimize movement of the ball swage 45once it is engaged in the pulling head body 5 by application of apulling tension on the pulling cable 40. The ball swage head 55effectuates a stopping, engaging effect within the pulling head body 5and prevents the pulling cable 40 from slipping through the first endbore 17 of the pulling head body 5. It is understood that the pullingcable 40, ball swage 55 or neck 50 can be manufactured from aluminum,steel, or any other sufficiently strong and rigid material as one ofskill in the art would contemplate for wire pulling uses.

As depicted in FIG. 5, in one preferred embodiment, the exposed surfaceof the neck 50 is tapped to create further friction between the neck 50and the end of the pulling cable 40. The tapped surface 60 can comprisea spiraling groove, or any other textured surface known in the art. Theresult is greater friction between the pulling cable 40 and ball swage55 to further prevent the pulling cable 40 from detaching from thepulling head body 5 and wire 65.

With reference to FIG. 8, it is also understood that a single pullingcable 40 can be split into one or more pulling cables for attachment toone or more wires 65 via one or more pulling head bodies 65. In thisway, a single wire pull is capable of pulling multiple cables throughthe conduits of a building's infrastructure.

Referring to FIG. 9, the crimp zone indicators 30 provide a recognizableand immediate sensory (i.e., via sight or feel) indication of apredetermined zone or area that is best suited for positioning of acrimping tool to engage, squeeze and form crimp dimples 70 on thepulling head body 5 for engaging an underlying wire 65. The crimpdimples 70, which can be formed by any crimping device having sufficientcrimping force to exert, are substantially centered with respect to thecrimp zone indicators 30. The dimples 70 created in one embodiment werecreated by using a hand-held eleven ton hydraulic press. It isunderstood that the crimping process has a zone of error that isacceptable with respect to placement of the crimp dimples 70.

In another embodiment of the invention, the size of the wire gaugedetermines the number of crimps required per crimp zone indicator 30.Referring to Table 1 by way of non-limiting examples, for wire gaugesless than or equal to 400 kcmil, each crimp zone indicator receives onecrimp on a side of the pulling head body 5. However, for wire gaugesgreater than 400 kcmil, each crimp zone indicator 30 receives twocrimps. Thus, for example, a 500 kcmil pulling head body 5 having twocrimp zone indicators 30 would comprise a total of four crimp dimples70. Furthermore, two crimp dimples 70 on the same crimp zone indicator30 are positioned 180 degrees apart.

Referring to FIG. 10 and by way of non-limiting example, and consistentwith embodiments of the invention, a method for attaching a pulling headbody 5 to a pulling cable 40 and wire 65 is illustrated. At step 100, apulling cable 40 is inserted through the first end 15 and into the firstend bore 17 of the pulling head body 5. At step 110, a ball swage 45 iscrimped to the attachment end of the pulling cable 40, and a pullingtension is applied to the pulling cable 40 so that the ball swage head55 engages with the second tapered surface 18 of the pulling head body5. As such, the pulling cable 40 is fixed to the pulling head body 5. Atstep 115, a wire 65 is inserted into the second end 20 and through thesecond end bore 23 until the wire 65 is fully inserted into the pullinghead body 5 and in contact with the ball swage head 55. At step 120, theoperator visually locates the one or more crimp zone indicators 30 onthe outer surface 10 of the pulling head body 5. At step 125, theoperator uses a hydraulic crimping device to crimp the pulling head body5 against the wire 65 at approximately the crimp zone indicators 30 sothat the resulting crimp zone dimples 70 are substantially centered withrespect to the crimp zone indicators 30. Once the wire 65 is securedwithin the pulling head body 5, the wire can be pulled as desiredthrough the building's infrastructure, as recited in step 130.

It will be appreciated by those skilled in the art that changes could bemade to the embodiments described above without departing from the broadinventive concept thereof. It is understood, therefore, that theinvention disclosed herein is not limited to the particular embodimentsdisclosed, but it is intended to cover modifications within the spiritand scope of the present invention as defined by the appended claims.

What is claimed is:
 1. A pulling head body for pulling wire, the pullinghead body comprising: a first end and a second end; a longitudinal boreextending from the first end, and the second end; one or more crimp zoneindicators, wherein the crimp zone indicators are positioned on an outersurface of the pulling head body; wherein each of the one or more crimpzone indicators indicates an optimal position for crimping the pullinghead body against a wire; wherein a pulling cable is inserted into thefirst end of the pulling head body through the first end bore; andwherein the pulling cable is secured to the pulling head body via a ballswage comprising a tapped ball swage neck.
 2. The pulling head body ofclaim 1, wherein the position of the one or more crimp zone indicatorsdepends on the gauge of the wire.
 3. The pulling head body of claim 1,wherein the pulling head body comprises a first end bore and a secondend bore.
 4. The pulling head body of claim 3, wherein the wire isinserted into the second end of the pulling head body through the secondend bore.
 5. The pulling head body of claim 3, wherein the one or morecrimp zone indicators indicate a position of a tapped surface within thesecond bore of the pulling head body.
 6. The pulling head body of claim1, wherein a neck of the ball swage is crimped to the pulling cable. 7.The pulling head body of claim 1, wherein the one or more crimp zoneindicators indicate one or more approximately maximum points of contactbetween the pulling head body and the inserted wire.
 8. The pulling headbody of claim 1, wherein the one or more crimp zone indicators areflush, etched, or raised with respect to the outer surface of thepulling head body.
 9. The pulling head body of claim 1, wherein the oneor more crimp zone indicators are notches, grooves, depressions,striations, or ridges.
 10. The pulling head body of claim 1, wherein theone or more crimp zone indicators are positioned on one or more sides ofthe pulling head body.